Optical recording medium and manufacturing method thereof

1. An optical recording medium comprising: an inorganic recording layer; and a protective layer including a composite oxide containing an indium oxide on at least one surface of the inorganic recording layer, wherein, the composite oxide is represented by the formula (In 2 O 3 ) 1-X (A) X , and where A is cerium oxide or gallium oxide and X satisfies a range of 0.15≦X≦0.75.

2. The optical recording medium according to claim 1 , further comprising: a heat accumulation layer between the inorganic recording layer and the protective layer, wherein, a recording and/or reproduction laser beam is applied from a side of the heat accumulation layer or a side opposite to the heat accumulation layer toward the inorganic recording layer.

3. The optical recording medium according to claim 2 , wherein the heat accumulation layer includes ZnS and SiO 2 .

4. The optical recording medium according to claim 1 , wherein the protective layer is provided on both sides of the inorganic recording layer.

5. The optical recording medium according to claim 1 , wherein the inorganic recording layer includes ZnS, SiO 2 , and Sb.

6. A manufacturing method of an optical recording medium comprising the steps of: providing an inorganic recording layer; and providing a protective layer including a composite oxide containing an indium oxide on at least one surface of the inorganic recording layer, wherein, the composite oxide is represented by the formula (In 2 O 3 ) 1-X (A) X and, where A is cerium oxide or gallium oxide and X satisfies a range of 0.15≦X≦0.75.

7. The manufacturing method of an optical recording medium according to claim 6 , wherein, the protective layer is formed by a direct-current sputtering method.